That decision means Williams could face one of the Grand Slam tournament's top eight seeded players as early as the third round.
The 29-year-old American leads active women with 13 major championships, including three at Flushing Meadows - in 1999, 2002 and 2008. She recently won consecutive hard-court tuneup tournaments at Stanford and Toronto, making her one of the favorites to win the US Open, which starts next Monday.
A former No 1, the American is ranked 29th this week. That's up from 175th in July, a few weeks after she returned to the tour following nearly a year off because of a series of health problems.
"After careful deliberation regarding Serena Williams' seeding, we decided to maintain the objective criteria in place to determine the women's singles seeds at this year's US Open," tournament director Jim Curley said in a statement released Tuesday by the U.S. Tennis Association.
Chris Evert, an 18-time major champion, thought the tournament erred by not lifting Williams' seeding.
"It hurts the field, is what it does. It really doesn't hurt Serena as much as it hurts the other players. One of the top seeds will get her in the third round," said Evert, who will call US Open matches for ESPN2. "I think they could have made a much better judgement call."
In the past, Grand Slam tournaments have taken into account factors other than the official rankings when determining seedings.
At the most recent major tournament, Wimbledon, two-time defending champion Williams was moved up to No 7 in the seedings, 19 spots higher than her ranking at the time, even though it was only the second tournament of her comeback. She wound up losing in the fourth round at the All England Club.
Her older sister Venus, a five-time Wimbledon champion, also was bumped up in the seedings there. But Venus Williams isn't seeded at all for the US Open, which she won in 2000 and 2001; she's ranked 36th this week.
Top-ranked Caroline Wozniacki, the 2009 US Open runner-up, is also No 1 in the women's singles seedings announced on Tuesday, followed by Vera Zvonareva, last year's losing finalist.
Two-time reigning US Open champion Kim Clijsters, who is ranked No 3, will miss the tournament this year with a stomach muscle injury. Fourth-ranked Maria Sharapova, the 2006 champion in New York, moves up to third in the seedings.
The men's seedings are to be announced on Wednesday, and the draw for the year's last Grand Slam tournament is on Thursday.
